Food allergy, which affects 1-2% of adults and 6-8% of children in the US, is defined as an immediate adverse reaction to components found in food products. The allergic reaction is caused by pre-formed antibodies to food components which bind to special cells in the bloodstream, releasing chemicals which cause symptoms of an allergic reaction.
Symptoms of food allergy can include hives, vomiting, belly pain, dizziness, mouth/tongue and throat itching, and can even manifest as difficulty breathing, throat swelling, and in severe cases, coma and death.
The most common allergenic foods for young children are milk, egg, soy, and wheat. Food allergy in adults is most commonly caused by peanut, tree nut, fish and shellfish. Approximately 80% of young children outgrow allergies to milk and egg; however, only 20% of patients with nut and shellfish allergies lose their allergic reactions over time.
Since reactions can be life-threatening, prompt diagnosis and treatment of food allergy is extremely important. Allergies to food can be diagnosed at your allergist’s office by skin prick testing. This painless method involves putting a very small amount of each food allergen just under the skin, with results available in 15 minutes. Sometimes, physicians measure allergy antibodies in the blood to diagnose and follow patients with food allergy. The best test for food allergy, however, is to perform a “food challenge”, where the suspected food is eaten in increasing amounts under close supervision at an allergist’s office. It is important to note that allergies change over time, and new allergies can appear at any time regardless of age, so it is best to consult your allergist if you have any new reactions or concerns about food.
Currently, treatment for food allergy is strict avoidance of the offending food. This involves reading ingredient labels and being very careful when dining outside of the home. Symptoms of an allergic reaction should be treated with injectable epinephrine, also known as an EpiPen, which should be carried at all times. In some cases, Benadryl can be used for mild reactions. There is new and exciting research in the field of food allergy which may eventually lead to a cure for both children and adults, however none of these therapies are approved at the present time.
If you suspect that you or your child may have a food allergy, come and visit your allergist -- we can help!
--- By Dr. Katharine S. Nelson